The invention relates to a device for introducing fuel into the combustion chamber of an internal combustion engine, comprising an injection valve for withdrawing compressed gas from the cylinder and injecting the gas together with the supplied fuel into the cylinder, with a mixing chamber in the front part of the valve for the purpose of gas storage, into which mixing chamber fuel may be introduced by one or more fuel flow passages opening into the mixing chamber, the injection valve being provided with a lifting valve for control of the gas exchange between the combustion chamber and the mixing chamber in the front part of the valve, and the seat of the lifting valve separating the mixing chamber from the combustion chamber, the orifice of the fuel flow passage opening into the mixing chamber being located in the area of the seat of the lifting valve.
For extremely lean operation a reproducible stratification of the fuel-gas mixture must be obtained in the combustion chamber, especially at part-load. This will only be possible if mixture preparation in the mixing chamber can be reproduced with constant results.